Unable to get the response from JSON

Question

I am new to android. Well what I am trying to do in the following code is making an http request sending to a php file from where json gets the response. In the php file I am trying to show the city names starting from A. Whenever I am running the code I am getting this error: "org.json.jsonexception value doctype of type java.lang.string cannot be converted to jsonarray". All The related Threads are of no help or i am not able to understand the solution given there. Here is my Java Code

MainActivity.java

package com.list;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.net.ParseException;
import android.os.Bundle;
import android.util.Log;

import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

JSONArray jArray;
String result = null;
InputStream is = null;
StringBuilder sb=null;


int ct_id;
String ct_name;



@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


TextView textview1 = (TextView)findViewById(R.id.textView1);
textview1.setText("Erqem");

 ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
//http post
try{
     HttpClient httpclient = new DefaultHttpClient();
     HttpPost httppost = new HttpPost("http://10.0.2.2/city.php");
     httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
     HttpResponse response = httpclient.execute(httppost);
     HttpEntity entity = response.getEntity();
     is = entity.getContent();

     }catch(Exception e){
         Log.e("log_tag", "Error in http connection"+e.toString());
    }
//convert response to string
try{
      BufferedReader reader = new BufferedReader(new InputStreamReader(is,"UTF-8"),8);
       sb = new StringBuilder();
       sb.append(reader.readLine() + "\n");

       String line="0";
       while ((line = reader.readLine()) != null) {
                      sb.append(line + "\n");
        }
        is.close();
        result=sb.toString();
        }catch(Exception e){
              Log.e("log_tag", "Error converting result "+e.toString());
        }

//paring data
try{
      jArray = new JSONArray(result);
      JSONObject json_data = new JSONObject();
      json_data=null;
      for(int i=0;i<jArray.length();i++){
             json_data = jArray.getJSONObject(i);
             ct_id=json_data.getInt("CITY_ID");
             ct_name=json_data.getString("CITY_NAME");

             textview1.setText(ct_name);
             }

      }

      catch(JSONException e1){
          Toast.makeText(getBaseContext(), "No City Found"+e1.toString() ,Toast.LENGTH_LONG).show();
          Log.e("log_tag", "Error converting result "+e1.getMessage() );
      } catch (ParseException e1) {
            e1.printStackTrace();
    }
}
}

php file

<?php
header('Content-type=application/json; charset=utf-8');
mysql_connect("","root","");
 mysql_select_db("Deal");
 $sql=mysql_query("select * from CITY where CITY_NAME like 'A%'");
 while($row=mysql_fetch_assoc($sql)) 
 $output[]=$row; 
 print(json_encode($output));
 mysql_close();

?>

Any Help would be appreciated.Thanks.

You should log the response you get before you try to parse it and check what you get. Have you tried to run the url from the emulator browser? — WarrenFaith, Apr 01 '13 at 21:16
what is the output you are trying to parse? please update your question with it — laplasz, Apr 01 '13 at 21:19
@WarrenFaith As i am very much new in android. could you please explain your point in more detail? — james, Apr 01 '13 at 21:19
If I were a betting man (and I'm not), I'd say you're getting an error message back from the server, rather than json. Log your response, like @WarrenFaith said. — 323go, Apr 01 '13 at 21:19
Furthermore, your code will CRASH any modern (4.x+) Android device with a NetworkOnMainThreadException. — 323go, Apr 01 '13 at 21:20
@323go How should I log my response? It would be great if you gave me an answer — james, Apr 01 '13 at 21:25
what is the result of this log - you can find it in LogCat, are you using Eclipse? http://stackoverflow.com/questions/3280051/how-to-enable-logcat-console-in-eclipse-for-android — laplasz, Apr 01 '13 at 21:25
@laplasz the same as written above org.json.jsonexception value doctype of type java.lang.string cannot be converted to jsonarray — james, Apr 01 '13 at 21:28
please put this log statement before jArray = new JSONArray(result); — laplasz, Apr 01 '13 at 21:30
@laplasz I posted this Log.d("log_tag", " converting " ); before the jArray = new JSONArray(result); and could see "converting" in logcat — james, Apr 01 '13 at 21:34
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/27355/discussion-between-laplasz-and-james) — laplasz, Apr 01 '13 at 21:35

score 2 · Accepted Answer · answered Apr 01 '13 at 21:49

2

maybe you are using incorrect address, please try 10.0.2.2:8080/city.php

answered Apr 01 '13 at 21:49

laplasz

3,111
1
25
35

Thanks alot; I have been wasting my time for so long on this small problem. – james Apr 01 '13 at 21:51

Unable to get the response from JSON

1 Answers1